Issue 1898 in lilypond: Unifies mensural ligatures with blot-diameter

New issue 1898 by address@hidden: Unifies mensural ligatures with
blot-diameter

http://code.google.com/p/lilypond/issues/detail?id=1898
The new mensural style introduced with commit
0dcc93c0a5a97d048db2f7631966f41ae0059ab5 created some ugliness's in
mensural ligatures.
This patch fix these. I also added serifs to flexas.
Regards,
Bertrand
Description:
Unifies mensural ligatures with blot-diameter.
Reverts some changes of commit 0dcc93c0a5a97d048db2f7631966f41ae0059ab5
Use blot-diameter either in C and MetaFont.
Please review this at http://codereview.appspot.com/5030053/
Affected files:
M lily/mensural-ligature.cc
M mf/parmesan-noteheads.mf